Basil Sauce Recipe

Peel and finely dice the onion so pieces are roughly 1/4-inch. Peel and mince the garlic. Core the bell peppers, remove seeds and membranes, and cut into 1/2-inch dice. Rinse and pat dry the fresh basil leaves; stack and chiffonade (roll leaves and slice into thin ribbons). Measure out seasonings and liquids.

Sweat the aromatics

Heat a large skillet or medium saucepan over medium heat. Add the olive oil and let it warm until shimmering but not smoking (about 1 minute). Add the diced onion and a pinch of salt, and sauté, stirring occasionally, until translucent and soft, about 5–7 minutes.

Add garlic and peppers

Add the minced garlic and diced bell peppers to the pan. Sauté for 4–6 minutes until the peppers soften and the garlic is fragrant but not browned. Stir frequently to avoid burning.

Push the vegetables to the side of the pan, add the tomato paste and cook 30–45 seconds, stirring, to caramelize slightly. Stir the tomato paste into the vegetables, then add the crushed tomatoes and broth. Scrape up any browned bits from the bottom of the pan. Bring the mixture to a gentle simmer.

Add the dried oregano, red pepper flakes, black pepper, and sugar (if using). Taste and season with salt to your preference. Reduce heat to maintain a low simmer and cook, uncovered, for 12–15 minutes to meld flavors and slightly thicken the sauce.

Remove the pan from heat. Stir in the chiffonaded fresh basil leaves until wilted (about 30–60 seconds). If using, whisk in the butter for a glossy finish and the lemon juice for brightness. Taste and adjust salt, pepper, or red pepper flakes as needed.

For a smoother, more uniform basil sauce, allow the mixture to cool slightly then transfer to a blender or use an immersion blender to puree to your desired consistency. If blending hot, ensure to vent the blender and work in batches. Return to the pan and gently warm before serving.

Serve hot over pasta, grilled chicken, fish, or as a dipping sauce. Store leftovers in an airtight container in the refrigerator for up to 4 days or freeze for up to 2 months. Reheat gently on the stovetop, adding a splash of broth if it has thickened too much.